Method for the production of a plant-based construction material and construction material obtained by means of said method

ABSTRACT

The construction material on a plant basis PB (preferably miscantus) contains a binder and a mineralizer composed of a defined mixture M 2  of calcium carbonate CaCO 3  and magnesium carbonate MgCO 3  that is prepared in an application-oriented manner, thereby resulting in a substantial improvement of its chemical, physical, and mechanical properties. The weight proportions of the components constituting said mixture M 2  are comprised between approx. 60% and approx. 95%, preferably between 2/3 and 9/10, for the CaCO 3 , and between approx. 5% and approx. 40%, preferably between 1/10 and 1/3, for the MgCO 3 . The method for producing said construction material is rationalized by previously admixing the mineralizer to the binder, preferably Portland cement of strength class 52.5, directly at the binder plant according to determined specifications to obtain a mixture M 1 . The weight proportions of the components constituting the mixture M1 are comprised between approx. 50% and approx. 90%, preferably between 6/10 and 4/5, for the binder, and between approx. 10% and approx. 50%, preferably between 1/5 and 4/10, for the mineralizer. In order to improve the solidification process, a fungicidal preparation is added to the mixing water. A universal construction material allowing innumerable applications can be produced from the aggregate {PB+M 1 }. The range of applications is further enlarged by adding another application-oriented mixture M 3  to said aggregate in defined proportions (e.g. gypsum for producing quick-assembly structural panels) or a flow agent in order to allow an extrusion method (e.g. for producing bar-shaped elements)).

CROSS REFERENCE TO RELATED APPLICATION

The present application is a 35 U.S.C. §§371 national phase conversionof PCT/CH2002/000583 filed 28 Oct. 2002. The PCT InternationalApplication was published in the German language.

BACKGROUND OF THE INVENTION

The invention refers to a plant-based construction material. Theinvention further refers to said plant-based construction material andobjects that are produced from this construction material.

Many construction materials produced from renewable primary productshave been developed and applied in order to satisfy the need for anecological construction method in accordance with nature. Variouscombinations on the basis of vegetable raw materials are known in theart.

Straw and clay are historical ecological construction materials thathave been used very frequently. However, their application is restrictedby the limited stability and durability of this material combination.Thus, timber framing infills made of straw and clay do not meet today'smodern requirements with respect to thermal and acoustic insulation.

Furthermore, various attempts have been made to use wood as a vegetableraw material in combination with cement as a sustainable constructionmaterial. However, the low strength resp. surface strength and theexcessive density and therefore relatively high weight of the resultingcomponents are often problematic. Also, the noise and heat insulatingproperties are relatively poor due to the high proportion of cementrequired as a binder.

In the search for a construction material having a maximum content ofrenewable primary material and good chemical, physical and mechanicalproperties, tests have also been made with miscantus (China reed). Dueto its high silicon content, inter alia, this plant genus offers idealproperties for processing into a stable and durable constructionmaterial.

However, the production of a viable construction material on the basisof a vegetable aggregate is only possible if the latter is bonded in thebinder matrix. This condition is fulfilled by a mineralization of thevegetable raw materials. Therefore, a qualitative utilization ofrenewable vegetable raw materials for modern, contemporary constructionsis subject to the quality and efficiency of this mineralization inparticular.

Furthermore, as is generally known, constructions require the use ofdifferent structural components and elements having specific propertiesaccording to the intended application. Thus, besides the components forthe construction e.g. of walls, there are other elements such asprefabricated plasterboards.

Accordingly, the problem is to produce a universally applicableplant-based construction material, i.e. a construction material that issuitable for virtually all conceivable applications due to a basiccomposition that is adaptable in view of the intended application andthus of the required properties and, as the case may be, supplementableby specific, also application-oriented additives.

According to the disclosure of EP-1,108,696 A1, a premineralization ofrenewable fibrous raw material particles such as wood, hemp, and/or reedparticles is achieved by means of cement, preferably Portland cement asa mineralizer. Here, the premineralization of the vegetable rawmaterials is accomplished in a separate process step, after which theraw materials treated with the mineralization liquid are dried. Thepretreated plant parts may then be used for producing concrete ormortars. The drawback of this approach is that an additional treatmentof the vegetable raw materials for the purpose of premineralization isnecessary. An additional process step is also associated to additionalcosts, and the construction industry is forced to save additionalprocess steps due to the constant cost pressure. Increased costs forecological construction methods strongly reduce the attractiveness ofsuch methods and cannot bring about to the application of suchalternative plant-based construction materials instead of conventionalconstruction materials.

Therefore, according to WO-A-02/12145, a premineralization of thevegetable aggregate is omitted in order to make the production ofconcrete and mortars cheaper and simpler on the basis of this aggregateand still to obtain favorable properties with respect to thermalinsulation, acoustic insulation, bending and compression strength.However, particularly with regard to the selected mineralizer, thismight not be accomplished optimally. Furthermore, an adaptation of theconstruction material in view of different required properties is notbeing mentioned, so that the fields of application are expected to berelatively limited.

It is an object of the present invention to solve the problem set forthabove and to overcome the disadvantages of the prior art.

SUMMARY OF THE INVENTION

According to the invention, this object is attained by the constructionmaterial described below.

Particularly in comparison with the known construction materials of thesame category, the construction materials produced according to themethod of the invention distinguish themselves by a substantially betterbonding ability and by adapted mechanical properties. Furthermore theyare inexpensive and ecological due to the application of renewableprimary materials and the reduced number of process steps—while a muchsimpler and less expensive design of the production facilities may beprovided and an almost continuous production of the constructionmaterial of the invention is possible since an intermediate storage oreven an intermediary drying of the mineralized vegetable raw materialsis not necessary—and on the logistic level. Ultimately, the possibleapplications and fields of application of the construction materials ofthe invention are virtually inexhaustible.

Further details, characteristic features and advantages of the method ofthe invention and of the construction materials produced therewith willbe apparent from the following description of exemplary embodiments. Forpurposes of illustration, structural elements are described withreference to the following drawings:

BRIEF DESCRIPTION OF THE DRAWINGS

For purposes of illustration, structural elements are described withreference to the following drawings:

FIG. 1 shows a sound-absorbing structural element,

FIG. 2.1 shows a slope reinforcement block,

FIG. 2.2 shows a finned slope reinforcement block, and

FIG. 3 shows a slope reinforcement wall.

DESCRIPTION OF PREFERRED EMBODIMENTS

Miscantus (China reed), hemp shives, hemp fibers, softwood, sugar cane,straw (e.g. wheat or rye straw), switchgrass (panicum virgatum), Italianryegrass, reed are advantageously used as vegetable raw materialsindividually or in different combinations. The vegetable raw materialsare comminuted prior to use. Depending on the kind of raw material andon the kind of the desired construction material and the structuralelements that are to be produced therefrom, they are comminuted intoelongate particles of up to approx. 40 mm or into granules of up toapprox. 8 mm in diameter. Thus, for example, the desired fiber lengthmay range up to approx. 40 mm and the particle size comprised between 0and 8 mm if the construction material is to be used for the productionof external walls or building bricks whereas these values shouldpreferably range up to 2 mm if the construction material is intended forplastering.

A mixture M1 is admixed to the selected and comminuted plant basis PB ofvegetable raw materials in a single process step. Said mixture M1 iscomposed of a binder, for example Portland cement or a mixture ofdifferent Portland cements, but preferably Portland cement of strengthclass PZ 52.5, and of a mineralizer. The mineralizer is directly admixedto the Portland cement at the Portland cement works according to arecipe, i.e. in predefined, application-oriented resp.-dependentproportions. Thus, the mixture M1 is subsequently taken from a singlesilo and weighed by means of a scale before being supplied to a mixer inwhich PB and M1 are blended. As compared to the conventional methods[where the mixer for the mixture {PB+M1} is connected to two silos (oneof which contains the Portland cement and the other the mineralizer)through respective scales], this procedure results in a substantialreduction of the production costs of the construction material due tothe simplification of the installation and the reduction of the numberof process steps.

The weight proportions of the components constituting the mixture M1 arecomprised in a range of approx. 50% to approx. 90%, preferably between6/10 and 4/5, for the Portland cement and in a range of approx. 10% toapprox. 50%, preferably between 1/5 and 4/10, for the mineralizer.

The mineralizer is composed of a defined, application-orientedresp.-dependent mixture M2 of calcium carbonate CaCO₃ and magnesiumcarbonate MgCO₃, the weight proportions being comprised in a range ofapprox. 60% to approx. 95%, preferably between 2/3 and 9/10, for CaCO₃and in a range of approx. 5% to approx. 40%, preferably between 1/10 and1/3, for MgCO₃. The practical applications have shown that thiscomposition of the mineralizer ensures a substantially better bondingability of the vegetable raw materials and therefore a better bond inthe matrix than the mineralizers of the prior art.

The mixture obtained from mixtures PB and M1 can now be mixed into apredetermined quantity of mixing water that corresponds to a desiredconsistency K_(i) (K_(i)=stiffness of the fresh concrete; K₁=moisterthan earth-moist; loose when shaken; K₂=just soft, cloddy when shaken;K₃=soft to liquid; source: Lüger).

A number of advantages are noted due to the above-defined compositionand its interaction. Thus, it could be observed that the solidificationbegins after a very short time already, namely approx. 75 minutes aftertempering, and that the setting process is accelerated. Furthermore, ascompared to all known construction materials, including plant-basedconstruction materials, the volume weight is reduced, bulk porosity ishigher, steam diffusion and thermal insulation are improved, and theproperties with regard to compression strength, tensile strength, andbending strength values—which are significantly superior to the DINprescriptions for concrete and mortars—are substantially increased.

The mixture {PB+M1} represents an all-purpose basic mixture, so tospeak, thereby allowing multiple and advantageous applications. As thecase may be, it may be sufficient just to adapt the proportions of themixture components M1 (=binder+mineralizer M2) and/or M2 (=calciumcarbonate+magnesium carbonate) for a given PB volume. These adaptationsare easily performed by those skilled in the art in accordance with theapplication of the construction material, i.e. the required propertiesof the construction material.

Another mixture M3 that will be discussed in more detail hereinafter maybe admixed to the all-purpose basic mixture. The specialist will ofcourse take this mixture into account in the mentioned adaptation.

Furthermore it has been found that the beginning of the solidificationand the following setting process may be substantially delayed bysporadically appearing fungus formation. In this connection, thefollowing fungi are cited on the basis of an analysis performed at theHumboldt University in Berlin: “Alternia” (blue coloration), “Fusarium”(red coloration) and “Penicillium” (yellow coloration). It is thereforeadvantageous to add a fungicidal preparation to the mixing water to makethese fungi ineffectual. This may e.g. be achieved by adding 2/3 litersof sodium hydroxide to 1,000 liters of mixing water. Whenever mixingwater is mentioned in the present description, it is implied that thewater is enriched in this manner.

If the construction material is e.g. intended for the erection ofexternal walls or for the production of building bricks resp. moldedconcrete bricks or hollow blocks, it is advantageously composedaccording to the following specifications:

-   -   PB=1 m³, preferably miscantus (comminuted according to the above        specifications);    -   M1=300 kg, composed of 75 kg of mineralizer according to M2 and        of 225 kg of Portland cement (weight proportions 25% to 75%);    -   M2=composed of 60 kg of calcium carbonate and of 15 kg of        magnesium carbonate (weight proportions 80% to 20%);    -   mixing water=approx. 300 l.

It has been found that the products obtained from this constructionmaterial distinguish themselves by excellent properties with regard toweight, bending strength, tensile strength, compression strength,thermal insulation and acoustic insulation.

In this regard, applications such as e.g. sound-insulating and-absorbing structural elements will now be described for purposes ofillustration with reference to FIGS. 1-3.

In order to improve the quality of life along freeways and roads-and toreduce the noise exposure of the residents, sound-absorbing structuralelements are connected to form noise barriers. The primary purpose ofthese structures is to reduce the noise exposure in the areas behindthese walls as seen in the direction of the noise source. It is acomprehensible desire of the concerned communities that these structuresin particular should be selected according to ecological aspects.Surprisingly it has been found that specifically the production ofsound-absorbing walls from preponderantly vegetable raw materialsaccording to the technical teaching of the invention not only takes intoaccount the ecological aspects but that precisely the sound-absorbingproperties of the construction material in combination with thegeometrical relationships of the sound-insulating structural elements ofthe invention provide the improved results as compared to the structuralelements that are conventionally used for noise barriers.

A sound-absorbing structural element according to an advantageousembodiment of the invention is illustrated in FIG. 1. 85 percent byweight of miscantus and 15 percent by weight of softwood shavings areused as vegetable raw materials for the element. 300 kg of the mixtureM1 are used per cubic meter of the vegetable raw material, and theconstruction material is subsequently poured into a mold. After setting,the material density of the obtained structural element is comprisedbetween 450 and 600 kg/m³ depending on the particle size and theresulting porosity of the vegetable constituents.

The sound-absorbing structural element is preferably provided with fins2 to enlarge the sound-absorbing surface area.

These structural elements are e.g. produced with a height of 2.90 m anda length of 4.00 m.

In accordance with a particularly preferred embodiment of the invention,the sound-absorbing structural element is built up of two layers. Thus,it is composed of a supporting layer 3 and of an absorber layer 4. Thestructural element itself has a thickness h of 25 cm. Supporting layer 3with a density of 1,250 kg/m³ has a supporting function, whereasabsorber layer 4 with a density of 500 kg/m³ mainly serves a soundinsulating function. To this end, absorber layer 4 comprises a layer fon which trapezoidal fins 2 are provided. Fins 2 have a height e of 10cm and a width d of 10 cm at the fin base. They have a width a of 6 cmat the fin head and a distance c of 3 cm between the fin bases. Thethickness of layer f amounts to 4 cm in the exemplary embodiment. Thetotal weight of structural element 1, related to the projected surfacearea, is 205 kg/m³.

According to another embodiment of the sound-absorbing structuralelement of the invention, the latter is made of a single layer resp. ofa single material. Here, the total thickness of themiscantus-softwood-hemp fiber lightweight concrete construction materialis h=20 cm. The fin height e is 8 cm, the width of fins 2 at the finhead a=4 cm and the distance between fins 2 at the fin base c=4 cm.

A remarkable fact is that the sound-absorbing structural elementsexhibit a very high resistance to road salt. This is importantparticularly for applications as sound barriers on freeways, which arestrongly exposed to spray water containing road salt in the winter.

The sound-absorbing properties have been examined according to methodsthat are standardized in DIN/EN 20 354, and it has been found that thesound absorption level of the sound-insulating structural elements ofthe invention is comprised between 0.71 and 0.88 at a frequency of 250Hz to 5,000 Hz.

The sound-absorbing surface area of the structural elements isadvantageously increased by an additional segmentation of fins 2. Thethus created pyramidal projections lead to an increase of thesound-absorbing surface area so that 1.96 m² of sound-absorbing surfacearea per square meter of projected surface area of the sound-insulatingstructural elements are obtained.

Furthermore, the plant-based construction material can also beadvantageously used for producing slope reinforcement blocks 5. FIG. 2.1shows such a cuboidal slope reinforcement block 5 for a form-fittingassembly of several slope reinforcement blocks 5. For a form-fittingassembly of several blocks, each slope reinforcement block 5 comprises atenon 8 and a groove 9. On the side facing the soil, a recess 7 isprovided which is filled up by the adjacent soil 12 when the block isused for the formation of a slope reinforcement wall. Recess 7 isfurthermore advantageous in that the block is additionally secured bythe soil.

According to FIG. 2.2, sound-absorbing fins 2 are provided on the sideof slope reinforcement block 6 opposite the soil 12. The block is thusfunctionally provided with an increased sound absorption, thereby makingit preferentially applicable for slope reinforcement walls alongfreeways or roads.

A slope reinforcement wall 10 composed of slope reinforcement blocks 5is schematically illustrated in FIG. 3. To this end, slope reinforcementblocks 5 are adjoined by a form-fitting introduction of tenons 8 incorresponding grooves 9. In one embodiment of the invention, slopereinforcement wall 10 is inclined at an angle á of approx. 10 degreeswith respect to the perpendicular. Further provided is a foundation 11,which essentially absorbs the vertical forces from slope reinforcementwall 10.

Geo fleece mats 13 are interposed horizontally between the layers of theearth. Geo fleece mats designed as tension bands are provided inintervals to absorb the horizontal forces from the slope reinforcementwall.

Furthermore, according to a preferred embodiment of the invention, theconstruction material of the invention allows to produce structuralelements that are even applicable as ceiling elements. To this end, theceiling elements are reinforced with hemp armoring ropes, the latterhaving a diameter of 12 mm or more. The spacing of the armoring ropesand the arrangement of the distributors (see below) are determined inaccordance with the static requirements.

In one embodiment of the invention for ceiling elements, the armoringropes are parallelly arranged in the ceiling element at intervals of 10cm. Furthermore, hemp ropes of a diameter of 8 mm are provided in theceiling element at intervals of 30 cm as distributors.

In this manner, structural elements having a width of up to 2.5 m and aspan of up to 5 m can be realized. It can be proved statically that theapplication of hemp ropes of a diameter of 12 mm provides a reinforcingeffect that is comparable to the application of steel of a diameter of 6mm (prestress).

Thus, the construction material of the invention allows a large numberof applications and products. According to a further embodiment of theinvention, a construction material having a high porosity is used as afilling material for a timber framing. In this case, the timber framingfulfills the static function of the structural element while theplant-based construction material provides excellent thermal insulationand noise protection properties. The formulation of a lightweightconcrete for wall elements fulfilling an insulating and infill functionis indicated as follows:

For 1 m³ of the construction material of the invention,

-   60% of miscantus chaff-   20% of softwood shavings-   20% of hemp shives and fibers-   240 kg of mixture M1-   210 l of water    are directly blended.

Furthermore, the construction material may e.g. be pressed to form aperforated building brick for conventional work. Such a building brickhas a width of 30 cm, a height of 24 cm, and a length of 36.5 cm. Thevolume of the building brick is 26.28 dm³, the hollow spaces with avolume of 7.04 dm³ making up a proportion of 27%. Its weight is 15.50kg. A composition according to the invention of the vegetable rawmaterials of the construction material is 75% miscantus shavings and 20%softwood shavings with a hemp fiber proportion of 5% according to thedesired static strength.

As indicated above, starting from the mentioned all-purpose basicmixture, the method can be supplemented for producing specificconstruction materials by adding to this mixture (or, depending on theavailable equipment, to the mixture M1 or M2) another mixture M3composed of application-specific materials in application-specificproportions.

For producing e.g. prefabricated quick assembly structural panels, thismixture M3 consists of gypsum, preferably with a starch added. Thepanels, cut to a conventional size (e.g. length: 2,500 mm, width: 1,250mm, thickness: 13 mm), are coated on both sides with a special papermade from recovered paper and ready for painting. The constructionmaterial forming the core is applied between the paper sheets. Thisconstruction material is advantageously composed according to thefollowing specifications:

-   -   PB=1 m³, comminution 0 to 2 mm, preferably a mixture of        miscantus (85% volumetric content, i.e. 85 kg (specific weight        100 kg/m³)) and of softwood (15% volumetric content, i.e. 16.5        kg (specific weight 110 kg/m³));    -   M1=160 kg, composed of 60 kg of mineralizer according to M2 and        of 100 kg of Portland cement (weight proportions 37.50% to        62.50%);    -   M2=composed of 42 kg of calcium carbonate and of 18 kg. of        magnesium carbonate (weight proportions 70% to 30%);    -   gypsum=200 kg;    -   mixing water=approx. 300 kg, remainder=approx. 15%,        corresponding to approx. 45 kg.

Thus, a specific weight of approx. 506 kg results. As compared to theconventional plasterboards, which have a specific weight of approx. 650kg/m³, this represents a significant weight reduction of more than 22%,which is an important advantage particularly with respect to logistics.

Another example of a mixture M3 is a conventional flow agent such aslignine sulfate, polycarboxylate, naphthalene sulfonate or naphthaleneacrylate. Indeed, it has been found surprisingly that extrudedstructural elements can be produced in this manner.

To this end, the construction material is extruded preferably after theaddition of flow agents. As compared to the conventional PVC bars (forthe manufacture of window profiles, amongst others), the obtainedprofiles exhibit a higher tensile strength and bending strength.

A structural element having a particularly high tensile strength of theconstruction material produced in this manner can be produced by using10 volume percent of hemp or miscantus fibers (or a mixture of thesefibers) as a component of the vegetable raw material. The integration ofthese fibers in the construction material matrix is excellent, and theirfiber structure provides outstanding tensile and bending strengths.

Like the plant-based construction materials of the prior art, theconstruction material described and claimed herein are breathable,recyclable, resource-saving and ecological, and free of toxicsubstances. However, the latter construction materials distinguishthemselves from those of the prior art and a fortiori from theconventional construction materials in that they have a lower volumeweight, better chemical, physical, and mechanical properties, and inthat they are more economical in manufacture. Not least, it will benoted that the construction materials of the invention cover a virtuallyinexhaustible range of applications and utilizations.

1. A construction material comprising: a plant-based component, said plant-based component is added in a volume sufficient to be an aggregate for said construction material, a mixture M1 of a hydraulic binder and a mineralizer, wherein the proportions of the components constituting the mixture M1 comprise between approximately 50 wt % and approximately 90 wt % of the hydraulic binder and between approximately 10 wt % and approximately 50 wt % of the mineralizer, and the mineralizer is comprised of a mixture M2 of calcium carbonate CaCO₃ and magnesium carbonate MgCO₃, the proportions of the components constituting the mixture M2 comprise between approximately 60 wt % and approximately 95 wt % of the CaCO₃ and between approximately 5 wt % and approximately 40 wt % of the MgCO₃.
 2. The construction material according to claim 1, wherein the proportions of the components constituting the mixture M1 comprise between 6/10 and 4/5 of the binder and between 1/5 and 4/10 of the mineralizer.
 3. The construction material according to claim 1 characterized in that wherein the proportions of the components constituting the mixture M2 comprise between 2/3 and 9/10 of the CaCO₃ and between 1/10 and 1/3 of the MgCO₃.
 4. Construction material according to claim 1, wherein for 1 m³ of plant-based component, the mixture M1 is comprised of 75 kg of mineralizer M2 and of 225 kg of binder in proportion of 25 wt % to 75 wt %, and the mixture M2 of 60 kg of calcium carbonate and of 15 kg of magnesium carbonate in proportions 80 wt % to 20 wt %.
 5. The construction material according to claim 1 wherein for 1 m³ of plant-based component, the mixture M1 is comprised of 60 kg of mineralizer according to M2 and of 100 kg of binder in proportions 37.50 wt % to 62.50 wt %, and the mixture M2 of 42 kg of calcium carbonate and of 18 kg of magnesium carbonate in proportions 70 wt % to 30 wt %, and 200 kg of gypsum or mixtures thereof.
 6. The construction material according to claim 1, wherein the plant-based component comprises materials comprising miscantus, hemp, softwood, sugar cane, straw, switchgrass or panicum virgatum, Italian ryegrass, reed, the materials being present individually or in different combinations, wherein the materials are comminuted.
 7. The construction material according to claim 6, wherein the comminuted particles are elongated particles comprising at least one of fibers of up to approximately 40 mm and a granulate of a grain size up to 8 mm.
 8. The construction material according to claim 6, wherein the plant-based component comprises a mixture of miscantus and softwood, with respective volumetric contents of 85% and 15% by volume.
 9. The construction material according to claim 6 wherein the plant-based component comprises a mixture of miscantus, softwood, and hemp, with respective volumetric contents of 75%, 20%, and 5% by volume.
 10. The construction material according to claim 1, wherein the mixture of plant-based component and the mixture M1 is mixed with a quantity of mixing water to produce a consistency K_(i) wherein K_(i) equals the stiffness of the fresh concrete moister than moist earth and loose when shaken.
 11. The construction material according to claim 10, wherein for 1 m³ of plant-based component, the quantity of mixing water is approximately 300 liters.
 12. The construction material according to claim 11, further comprising a fungicide admixed with the mixing water, by addition of approximately 2/3 liters of sodium hydroxide for 1,000 liters of mixing water.
 13. The construction material according to claim 1, wherein the binder is Portland cement of a standardized grade, said standardized grade being strength class 52.5.
 14. A method for producing a construction material wherein the construction material comprises a plant-based component, said plant-based component is added in a volume sufficient to be an aggregate for said construction material which contains a mixture M1 of a hydraulic binder and a mineralizer, wherein the proportions of the components constituting the mixture M1 comprise between approximately 50 wt % and approximately 90 wt % of the binder and between approximately 10% and approximately 50% of the mineralizer, and the mineralizer is comprised of a mixture M2 of calcium carbonate CaCO₃ and magnesium carbonate MgCO₃, the weight proportions of the components constituting the mixture M2 comprise between approximately 60 wt % and approximately 95 wt % of the CaCO₃ and between approximately 5 wt % and approximately 40 wt % of the MgCO₃ and at least one additional material; the method comprising: preparing the mixture M2 comprised of calcium carbonate CaCO₃ and magnesium carbonate MgCO₃ with the at least one additional material and admixed with the mixture M1 of the binder and the mineralizer in water to a consistency K_(i).
 15. The method for producing a construction material according claim 14, wherein the mixture M2 comprised of calcium carbonate CaCO₃ and magnesium carbonate MgCO₃, at least one additional material, and the mixture M1 comprised of the binder and the mineralizer is extruded.
 16. The method according to claim 14, wherein the preparation of the mixture takes place in a single process step, and the mineralizer and the at least one additional material are previously admixed with the binder.
 17. The construction material according to claim 1, further comprising gypsum.
 18. The construction material according to claim 17, further comprising starch.
 19. The construction material according to claim 18, further comprising a flow agent.
 20. The construction material according to claim 5, further comprising starch.
 21. The construction material according to claim 20, further comprising a flow agent.
 22. The construction material according to claim 1, further comprising a flow agent.
 23. The construction material according to claim 5, further comprising a flow agent. 